ZF S5D 310Z M60 to M50 Transmission Bell Housing Swap Possible?

[VonRiesenberger]

Hello people of the forum. I've come here to humbly and respectfully call upon the e34 OG advice, more specifically with the hope of acquiring knowledge and wisdom into whether I should choose a path seldom if at all taken, a proverbial present day e34 frontier...and maybe a possible transmission repair and restoration to tag along.


Here's my situation. I have a future 5-speed swap that I'm collecting parts for.


Currently I have a solid and healthy ZF S5D 310Z 5 speed, unfortunately it's the wrong one with the m60 bell housing that was removed from my 530i m60b30 car.
I didn't have thoughts on doing anything to it as such until I saw that there's a local (non-working) ZF S5D 310Z 5 speed for sale and it having the correct m50 bell housing for like $100ish dollars...pennies compared to what a working one goes for. No details on what is wrong with it but I'm assuming its gearing related as pieces can be heard rattling inside when shaken.


Here's what I'd like to know.


1. First and foremost, is it possible to swap a ZF S5D 310Z m50 bell housing onto the rear gearing section of an originally m60 ZF S5D 310Z 5 speed transmission?
2. If bell housings are swap-able, what are the major considerations I should know before I attempt to even think about doing this?
3. I assume there's plenty of "things" that will need to be acquired or replaced to make the re-assembly possible...with the exception of buying directly from ZF and their catalog, is there anywhere else I acquire those parts. Furthermore are there any resources/people I should use/contact I may not know of?


Why go through all this effort?...there's a few reasons but one of which I rarely stumble upon...and that's not seeing a post where someone has asked the same question.
To those thinking of suggesting I just sell the one that wont fit and purchase the correct one...I do appreciate your thoughtful gesture, but please spare the internet your mediocrities, respectfully.

[dannyzabolotny]

The short answer is yes, you can swap the bellhousings.

The long answer is: take a look at your ZF. Whereas some transmissions like the Getrag 420g have bellhousings that are just bellhousings, the ZF 310z/320z bellhousing is actually the entire front half of the transmission. Look to see where the case splits.

So to remove the bellhousing, you'll need to pull the whole front of the bellhousing/case off. There's an input bearing that's pressed into the bellhousing... if you remove the input sleeve and input seal, you'll find an extremely stubborn snap ring in there. Get that out and then you'll need to make a custom tool using the input sleeve, to basically press the input shaft out of the bearing that is in the bellhousing. You'll also have to contend with the shift arms, as they'll be all over the place as you pull things apart and you'll need to carefully maneuver them to reassemble the transmission correctly.

If you really want to try doing this (and potentially ruin a transmission), here's the instruction manual from ZF on how to do so: https://drive.google.com/file/d/1gSh...ew?usp=sharing

[bluptgm3]

There is at least one thread on this forum that explains the trial/tribulation of separating the case half’s.
And there is the S5D 310Z/320Z internal differences, the S5D 320Z is able to handle slightly more torque. I do not know the internal differences.
Talk to BimmerWorld and/or Metric Mechanic.
ZF does not seem to sell to the GP and I have read that S5D 310Z/320Z internal components are NLA….